The present invention relates to the field of absorbent articles used for the containment of body fluids. More particularly the invention relates to the use of elastomeric ears for fitting these articles on the body of the wearer.
Disposable absorbent articles have long been used for the absorption of various kinds of bodily fluids. They have been used in various forms ranging from diapers for babies, to adult incontinence articles, to feminine health care products. Today, most of these articles employ the use of an absorbent pad sandwiched between a liquid permeable sheet and a liquid impermeable sheet. These articles may take various shapes and sizes depending upon their need and applicability. For example, a pad type structure may be used for feminine health care products. The article may be hourglass-shaped for use as a baby diaper, or it may take the shape of pants when it is used for toilet training for young children, or as a convenience device for adults having difficulty controlling their bladder.
Considerable effort has been expended by engineers to increase the use of the absorbent articles. This effort has been directed towards increasing functionality of the article, for example, by improving absorption, retention of multiple voids, less leakage, and enhancing ease of use and wearer comfort, such as improving fit and minimizing skin irritation. Further efforts include designing a better-looking product, by using printed backsheets and reducing the product's bulkiness. Other innovations include features such as visual indicators of “time to change” the article, “glow in the dark” articles, and articles with skin conditioners, etc.
Since such an article is usually worn throughout the day, it is very important to not only minimize skin irritation that may be caused by the article, but also to maximize the fit of the article on the body so as to increase the comfort of the wearer. Ease in wearing, cozy fitness for long periods of time, and freedom in body movement are just some of the desired features from such a product.
Diapers are one kind of absorbent article that have evolved over time from bulky, uncomfortable, leak prone, rectangular articles, to lightweight, long lasting, appealing looking products. Owing to the research and development in the field, the acceptability of diapers has increased to such an extent that they enjoy a 95% penetration in the US market.
One important area where significant development has occurred is in the way the diaper is fitted to the body. The hourglass-shaped design is one such innovation that was adopted by the industry in the 1980s. In the hourglass-shaped configuration, the diaper has a near rectangular crotch region. Above and below this region (i.e., at the shorter side of the rectangle) are relatively broad front and rear portions of the diaper. These sections together cover the front (i.e., the area above the crotch and below the stomach) and back portion (i.e., the bottom) of the wearer. The top edge of these sections (i.e., the front and rear) together form the waist portion of the diaper.
In order to have better coverage of the side portion of the body when a diaper is worn, these sections are progressively being redesigned with flaps projecting outwardly from both sides of the diaper. These flaps or “ears” not only give a fuller coverage to the body (and hence provides a better fit), but also provide a well-defined leg section.
The hourglass-shaped configuration as is commonly used today has relatively broad front and rear portions (with wing like protrusions) connected by a crotch section having an absorbent member. When a diaper is worn, it is positioned in such a way that the absorbent section covers the crotch of the wearer and the front section is folded over so as to cover the front portion of the wearer. The rear portion covers the bottom of the wearer. The outward projecting ears of the front portion (from the navel to the side of the body) are overlapped by the outwardly projecting ears from the rear portion (coming from the back of the body to the front). In this way, a full waist circle is formed. As mentioned earlier, the ears can be shaped in such a way so as to have well-defined leg openings.
In order for the diaper to stay in place there should be some way for the rear ears to be fixed to the front portion of the diaper. The industry has adopted various means for achieving this result, such as through the use of tapes and/or mechanical fasteners. Since fasteners such as tapes and other fasteners have a tendency to gradually loosen their grip during prolonged periods of wearing the diaper, it is desirable to have a configuration of ears and fasteners such that the diaper can be pulled and tightly fitted on the wearer. This would ensure a prolonged period of comfortable wearing.
U.S. Pat. No. 5,496,298 to Kuepper et al. discloses the construction of such ears. The ears disclosed in the reference are attached to the front and rear portions of the main body of the diaper. The ears are made of elastomeric material (for better body hugging fit), and are shaped to cover the side of the body (increasing leak protection). The ears are disclosed as being affixed to the body of the diaper along proximal edges at the outer periphery of the diaper. This type of attachment provides only limited room for expansion around the body of the wearer. Accordingly, the area available for increasing the waist fit in this configuration is only the ear portion. Therefore, increasing the stress on these ears can put a strain on the side of the body. Furthermore, since a small portion of material is available for providing a proper fit, the material is required to be of high quality. High quality elastomers add to the cost of the article.
U.S. Pat. No. 6,648,868 to Sayama et al. discloses the use of two bands of elastic members at the top and bottom edge of the front as well as the rear portion of the diaper. Although this configuration may have better performance in terms of leak protection, the use of elastic at the edges would strain the edges and consequently cut into the skin, making it difficult to wear the article for prolonged periods of time.
U.S. Patent Publication No. 2002151863 A1 to Toyoshima discloses the use of two elastic members at either side of the absorbent core. In such a configuration, the use of an elastic may irritate the skin. Furthermore, since the elastic is only provided along the sides of the article, the grip at the back of the body is not provided for.
Accordingly, it would be desirable to provide an absorbent article that not only has a better grip around the waist of the wearer, but is also minimally irritable to the skin. This would increase the prolonged continuous wearing of the article. It is also desirable to achieve such an article with minimal cost. The present invention has an objective to overcome the aforementioned drawbacks, and provide a better absorbent article.
Additional objectives of the present invention include providing a better fitting absorbent article, providing an absorbent article that is comfortable to wear for long periods of time, and providing a better fitting and comfortable absorbent article by using cost-effective material.